The proper development of multicellular organisms depends on a complicated series of molecular and cellular events orchestrated by genes. Systematic genetic screens for mutations in invertebrates such as Drosophila and the nematode, Caenorhabditis elegans, have revolutionized the understanding of the genetic mechanisms that underlie the development of these organisms by providing a direct link between an identified gene and the role it plays in development. In particular, the use of transposable elements, which move from one location to another within the genome, have been used to identify and characterize numerous genes that are essential for the development and survival for these invertebrate organisms. Until recently, large-scale genetic screens were not possible in vertebrates. This system of transposable element-mediated insertional mutagenesis applied to the zebrafish, Danio rerio, would provide invaluable information about the genetic mechanisms underlying the normal development of the vertebrate retina. In addition, this system could be used to determine the effects of mutating these genes as a tool for investigating the genetic control underlying inherited eye diseases in humans.